A mobile communication system has been developed to provide an audio service to a user while securing mobility of the user. Yet, the mobile communication system is gradually expanding its service area not only the audio service but also a data service and has developed to the extent as much as providing fast data service nowadays. Yet, since the currently providing mobile communication system is experiencing a lack of resources and users are requiring a faster service, a more advanced mobile communication system is required.
One of most important things of a next generation wireless access system is to satisfy data transfer rate demand. To this end, ongoing effort to develop various technologies including MIMO (multiple input multiple output), CoMP (cooperative multiple point transmission), a relay and the like is in progress. Moreover, in order to accommodate increasing wireless data demand, application of a heterogeneous network consisting of macro-pico or macro-femto is expanding.
As mentioned in the foregoing description, while a situation in which a user equipment can be placed is variously expanding due to the various technologies, it is necessary to have a method of appropriately measuring channel state of the user equipment in accordance with the situation in which the user equipment is placed.